Triethylamine → Cyclopropyl(2-(4-(2,4-difluorophenoxy)piperidin-1-yl)-3-(isopropylamino)-7,8-dihydropyrido[3,4-b]pyrazin-6(5H)-yl)methanone

Participants

Reaction Steps

To a solution of 2-(4-(2,4-difluorophenoxyl)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-3-amine TFA salt (18.0 mg, 0.035 mmol) in DCM (348 μL) at room temperature was added triethylamine (14.5 μL, 0.104 mmol) and cyclopropanecarbonyl chloride (6.4 μL, 0.070 mmol). The reaction was stirred for 10 min at room temperature. The reaction mixture was concentrated under reduced pressure and was purified by HPLC Method B, with the exception that a Waters SunFire™ C18, 5 μm, ID 30×75 mm column was used, using a 50% to 90% ACN gradient to give the title compound, as a TFA salt, as a yellow film (3.3 mg, 16%). 1H NMR (400 MHz, methanol-d4, mixture of rotamers) δ ppm 0.81-0.96 (m, 4H), 1.29 (m, 7H), 1.90-2.18 (m, 4H), 2.73 (m, 0.7H), 2.87 (m, 1.3H), 3.07 (m, 2H), 3.42 (m, 2H), 3.88 (m, 0.7H), 4.06 (t, J=5.7 Hz, 1.3H), 4.14 (m, 1H), 4.49 (m, 1H), 4.62 (s, 1.3H), 4.80 (s, 0.7H), 6.88 (m, 1H), 6.99 (ddd, J=11.2, 8.5, 3.0 Hz, 1H), 7.18 ppm (td, J=9.2, 5.6 Hz, 1H); ESI-MS m/z [M+H]+ 472.5.

Provenance & Evidence